An American Airlines 757 was unable to contact air traffic control (ATC) after taking off on a scheduled flight from New York's John F. Kennedy Airport. The incident, reported in the Aviation Herald, occurred yesterday, Wednesday, July 24, 2019.

The aircraft, a Boeing 757-200, was operating AA2234, the scheduled 7.00am departure from JFK and was bound for Dallas.

What happened?

The problem seemed to be that the aircraft's microphone stayed opened after departure and blocked the ATC frequency. It not only stopped further communication with ATC from AA2234, but it also impacted on departure radio contact for other flights.

ATC was able to get a heading instruction through to the flight but after confirming it back to ATC, the microphone stayed open, blocking the radio frequency.

After attempting to contact departure control several times, AA2234 realized they could not contact New York's ATC, leveled off as instructed at 5000 feet, and set their transponder to indicate loss of contact.

ATC was aware of what the problem was and tried to let the crew know their microphone was stuck.

Soon after, the microphone became unstuck and the frequency was operable again. However, the American Airlines flight crew did not respond to contact attempts from ATC. ATC issued frequency changes and cleared the flight to land back in New York on runway 04R.

The flight landed on 04R as per instructed. The aircraft had been in the air for some 30 minutes. The flight's arrival back into JFK was recorded and can be viewed here.

AA2234 was guided off the runway and remained on the ground for approximately six hours before operating the delayed flight to Dallas. The aircraft arrived safely into Dallas six and half hours late.

Is losing radio contact that uncommon?

Losing radio contact with ATC is unusual but not unknown. Arguably,  the most famous incident is Northwest flight 188 which went incommunicado for approximately one hour in October 2009. The flight from San Diego to Minneapolis also overshot its destination city by some 150 miles. The incident was a minor cause celebre and has since been subject to considerable investigation and analysis.

Yesterday's event on AA2234 was more prosaic - a blocked microphone.

Usually, the reasons why aircraft lose contact are predictable. It can occur as flights enter into different sectors with different frequencies. It is not unknown for the pilot to tune into the incorrect frequency.

Some airports and regional fields can have significant geographical features (for example, mountains) that can block radio contact.

According to an informed comment in an Aviation forum, it is not uncommon for ATC at some airports to temporarily lose radio contact with their aircraft several times a month. It is usually attributed to "VFR pilot error situations."

Finally

It is not known what caused the jammed microphone on yesterday's American Airlines flight. The incident highlights the reliance aircraft have on ATC, particularly in crowded airspace such as around JFK. There was a delay but the aircraft landed safely and no one was injured - and that's a pretty good outcome.

Simple Flying reached out to American Airlines for comment but received no response prior to publication.